Monday, January 20, 2014

Understanding UCR

When I was in the Navy I learned about something called Dead Reckoning navigation. This was the way that ships navigated before the days of GPS. The way it works is that if you start from a known point and you accurately record the direction, speed and time you travel you can navigate to any point on the globe. The first, and most important thing is starting from a known point.

In order to know where you are going, you have to know where you have been. 

Crime stats are a lot like this. In order to know if your agency’s crime suppression efforts are effective, you have to know where you started from. The FBI’s Uniform Crime Reports program or UCR is an important tool in collecting crime statistics from police agencies across the country. These crime statistics help you to know where your agency’s crime suppression efforts started from and where they are going.

First, a little background is in order. 

Way back in 1927 the International Association of Chiefs of Police (IACP) began work on a program to collect crime statistics from law enforcement agencies across the United States. In the early 1930’s this program was taken over by the US government and responsibility was given to the FBI to collect and analyze these crime statistics. Now, nearly every law enforcement agency in the United States reports crime data to the UCR program. 

There is a number of different types of crime data collected by the UCR program. Crimes are broken up into two broad categories Part 1 crimes and Part 2 crimes. However, Part 1 data is the most commonly used crime data in the UCR program. The crimes counted as Part 1 crimes are:

  • Murder
  • Rape
  • Robbery
  • Aggravated Assault
  • Burglary
  • Larceny
  • Vehicle Theft
  • Arson

Murder, Rape, Robbery and Aggravated Assaults are further classified as Violent Crimes while the remainder of the list are classified as Non-Violent Crimes. Obviously these aren’t all types of crime but they are a pretty good representative. 

So just what are these UCR stats good for?

Some people (often lazy journalists) think crime stats are to be used to pillory police chiefs. Others, usually small publishing companies, believe that UCR data is to be complied into simplistic lists which are then used to declare a city as the “most dangerous” in a press release which also just happens to announce the release of their paid “report”. The latter examples has gotten so common that the FBI’s UCR Program now issues prominent warnings on their UCR publications warning against the practice. These types of comparisons rarely take into account the differences in a community that can affect crime. 

The prevalence of crime in a community has quite a number of factors such as population demographics, economic and education factors, residents’ historic attitudes about crime, funding and support of police, etc. Since no two cities are identical, it’s really not a valid assessment to compare UCR crime numbers directly. 

The real value in UCR stats goes back to my illustration about dead reckoning navigation: In order to know where you are going, you have to know where you have been. UCR crime stats allow an agency to track consistent metrics year to year to determine how their agency is doing in their mission of crime suppression. While it isn’t terribly useful to compare one jurisdiction’s UCR crime numbers to another, it is a valid technique to compare a jurisdiction’s performance to their numbers in previous years. 

It can also be helpful to look at other agencies around yours to see if they are seeing the same increases or decreases in crime categories. If burglary is up in your jurisdiction, has it also gone up in a neighboring community? If so, the problem may be more widespread than just your jurisdiction. This may point to the need for a collaborative effort between these two jurisdictions to develop a solution. You aren’t directly comparing your burglary numbers to theirs but are seeing if there are similarities in the trends at the two jurisdictions. 

It is also worth keeping this next point in mind about UCR crime stats or any type of performance measures. Don’t freak out if you have a bad month or year. Not to belabor the point with nautical illustrations but this may be helpful. 

When you steer a ship, there is what called a compass repeater in the pilothouse that displays the direction or heading the ship is going. The helmsman will usually be given orders to steer a course of a specific direction. However, if you’ve ever used a compass you know that the needle will often move around a bit. It also takes some time for the ship’s rudder to have an effect on turning the ship. If the helmsman moves the wheel every time the compass needle bounces or he doesn’t allow for the time it takes for the rudder to have an effect on the ship’s course he’ll have a heck of a time steering the desired course. By the time the ship starts turning the compass needle may have bounced around in another direction or he’ll have oversteered the ship as he kept adding rudder input trying to get the ship to respond. New helmsman are often cautioned against “chasing the needle”. 

Crime stats are like that too. If every time the crime numbers spike your agency changes course, you will never be effective. Instead the question to ask is: “Is this increase part of a larger trend or just an isolated incident?” If it is an isolated incident, the numbers will likely smooth out the next month. Police agencies like big ships take time to change direction so don’t chase the needle. 

UCR crime statistics aren’t the only a performance measure an agency should use but they are probably one of the most important. 

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